package com.etcsoft.examples.yjstory;

import java.io.File;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;

public class FileTreeSystemSample2{
    
public static void main (String [] args) {
    final Display display = new Display ();
    final Shell shell = new Shell (display);
    shell.setText ("File Tree");
    shell.setLayout (new FillLayout ());
    final Tree tree = new Tree (shell, SWT.BORDER);
    File [] roots = File.listRoots ();
    for (int i=0; i<roots.length; i++) {
        TreeItem root = new TreeItem (tree, 0);
        root.setText (roots [i].toString ());
        root.setData (roots [i]);
        new TreeItem (root, 0);
    }
    
    tree.addListener (SWT.Expand, new Listener () {
        public void handleEvent (final Event event) {
            final TreeItem root = (TreeItem) event.item;
            TreeItem [] items = root.getItems ();
            for (int i= 0; i<items.length; i++) {
                if (items [i].getData () != null) return;
                items [i].dispose ();
            }
            File file = (File) root.getData ();
            File [] files = file.listFiles ();
            if (files == null) return;
            for (int i= 0; i<files.length; i++) {
                TreeItem item = new TreeItem (root, 0);
                item.setText (files [i].getName ());
                item.setData (files [i]);
                if (files [i].isDirectory()) {
                    new TreeItem (item, 0);
                }
            }
        }
    });
    
    Point size = tree.computeSize (300, SWT.DEFAULT);
    
    int width = Math.max (300, size.x);
    int height = Math.max (300, size.y);
    shell.setSize (shell.computeSize (width, height));
    shell.open ();
    while (!shell.isDisposed ()) {
        if (!display.readAndDispatch ()) display.sleep ();
    }
    
    display.dispose ();
    }
}
